xref: /freebsd/sys/dev/ichwd/ichwd.c (revision 2357939bc239bd5334a169b62313806178dd8f30)
1 /*
2  * Copyright (c) 2004 Texas A&M University
3  * All rights reserved.
4  *
5  * Developer: Wm. Daryl Hawkins
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * Intel ICH Watchdog Timer (WDT) driver
31  *
32  * Originally developed by Wm. Daryl Hawkins of Texas A&M
33  * Heavily modified by <des@FreeBSD.org>
34  *
35  * This is a tricky one.  The ICH WDT can't be treated as a regular PCI
36  * device as it's actually an integrated function of the ICH LPC interface
37  * bridge.  Detection is also awkward, because we can only infer the
38  * presence of the watchdog timer from the fact that the machine has an
39  * ICH chipset, or, on ACPI 2.x systems, by the presence of the 'WDDT'
40  * ACPI table (although this driver does not support the ACPI detection
41  * method).
42  *
43  * There is one slight problem on non-ACPI or ACPI 1.x systems: we have no
44  * way of knowing if the WDT is permanently disabled (either by the BIOS
45  * or in hardware).
46  *
47  * The WDT is programmed through I/O registers in the ACPI I/O space.
48  * Intel swears it's always at offset 0x60, so we use that.
49  *
50  * For details about the ICH WDT, see Intel Application Note AP-725
51  * (document no. 292273-001).  The WDT is also described in the individual
52  * chipset datasheets, e.g. Intel82801EB ICH5 / 82801ER ICH5R Datasheet
53  * (document no. 252516-001) sections 9.10 and 9.11.
54  */
55 
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD$");
58 
59 #include <sys/param.h>
60 #include <sys/kernel.h>
61 #include <sys/systm.h>
62 #include <sys/bus.h>
63 #include <machine/bus.h>
64 #include <sys/rman.h>
65 #include <machine/resource.h>
66 #include <sys/watchdog.h>
67 
68 #include <dev/pci/pcivar.h>
69 
70 #include <dev/ichwd/ichwd.h>
71 
72 static struct ichwd_device ichwd_devices[] = {
73 	{ VENDORID_INTEL, DEVICEID_82801AA, "Intel 82801AA watchdog timer" },
74 	{ VENDORID_INTEL, DEVICEID_82801AB, "Intel 82801AB watchdog timer" },
75 	{ VENDORID_INTEL, DEVICEID_82801BA, "Intel 82801BA watchdog timer" },
76 	{ VENDORID_INTEL, DEVICEID_82801BAM, "Intel 82801BAM watchdog timer" },
77 	{ VENDORID_INTEL, DEVICEID_82801CA, "Intel 82801CA watchdog timer" },
78 	{ VENDORID_INTEL, DEVICEID_82801CAM, "Intel 82801CAM watchdog timer" },
79 	{ VENDORID_INTEL, DEVICEID_82801DB, "Intel 82801DB watchdog timer" },
80 	{ VENDORID_INTEL, DEVICEID_82801DBM, "Intel 82801DBM watchdog timer" },
81 	{ VENDORID_INTEL, DEVICEID_82801E, "Intel 82801E watchdog timer" },
82 	{ VENDORID_INTEL, DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer" },
83 	{ 0, 0, NULL },
84 };
85 
86 static devclass_t ichwd_devclass;
87 
88 #define ichwd_read_1(sc, off) \
89 	bus_space_read_1((sc)->smi_bst, (sc)->smi_bsh, (off))
90 #define ichwd_read_2(sc, off) \
91 	bus_space_read_2((sc)->smi_bst, (sc)->smi_bsh, (off))
92 #define ichwd_read_4(sc, off) \
93 	bus_space_read_4((sc)->smi_bst, (sc)->smi_bsh, (off))
94 
95 #define ichwd_write_1(sc, off, val) \
96 	bus_space_write_1((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
97 #define ichwd_write_2(sc, off, val) \
98 	bus_space_write_2((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
99 #define ichwd_write_4(sc, off, val) \
100 	bus_space_write_4((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
101 
102 static __inline void
103 ichwd_intr_enable(struct ichwd_softc *sc)
104 {
105 	ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) | SMI_TCO_EN);
106 }
107 
108 static __inline void
109 ichwd_intr_disable(struct ichwd_softc *sc)
110 {
111 	ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) & ~SMI_TCO_EN);
112 }
113 
114 static __inline void
115 ichwd_sts_reset(struct ichwd_softc *sc)
116 {
117 	ichwd_write_2(sc, TCO1_STS, TCO_TIMEOUT);
118 	ichwd_write_2(sc, TCO2_STS, TCO_BOOT_STS);
119 	ichwd_write_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
120 }
121 
122 static __inline void
123 ichwd_tmr_enable(struct ichwd_softc *sc)
124 {
125 	uint16_t cnt;
126 
127 	cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
128 	ichwd_write_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
129 	sc->active = 1;
130 	if (bootverbose)
131 		device_printf(sc->device, "timer enabled\n");
132 }
133 
134 static __inline void
135 ichwd_tmr_disable(struct ichwd_softc *sc)
136 {
137 	uint16_t cnt;
138 
139 	cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
140 	ichwd_write_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
141 	sc->active = 0;
142 	if (bootverbose)
143 		device_printf(sc->device, "timer disabled\n");
144 }
145 
146 static __inline void
147 ichwd_tmr_reload(struct ichwd_softc *sc)
148 {
149 	ichwd_write_1(sc, TCO_RLD, 1);
150 	if (bootverbose)
151 		device_printf(sc->device, "timer reloaded\n");
152 }
153 
154 static __inline void
155 ichwd_tmr_set(struct ichwd_softc *sc, uint8_t timeout)
156 {
157 	ichwd_write_1(sc, TCO_TMR, timeout);
158 	sc->timeout = timeout;
159 	if (bootverbose)
160 		device_printf(sc->device, "timeout set to %u ticks\n", timeout);
161 }
162 
163 /*
164  * Watchdog event handler.
165  */
166 static void
167 ichwd_event(void *arg, unsigned int cmd, int *error)
168 {
169 	struct ichwd_softc *sc = arg;
170 	unsigned int timeout;
171 
172 	cmd &= WD_INTERVAL;
173 
174 	/* disable / enable */
175 	if (cmd == 0) {
176 		if (sc->active)
177 			ichwd_tmr_disable(sc);
178 		*error = 0;
179 		return;
180 	}
181 	if (!sc->active)
182 		ichwd_tmr_enable(sc);
183 
184 	/* convert from power-of-to-ns to WDT ticks */
185 	if (cmd >= 64) {
186 		*error = EINVAL;
187 		return;
188 	}
189 	timeout = ((uint64_t)1 << cmd) / ICHWD_TICK;
190 	if (timeout < ICHWD_MIN_TIMEOUT || timeout > ICHWD_MAX_TIMEOUT) {
191 		*error = EINVAL;
192 		return;
193 	}
194 
195 	/* set new initial value */
196 	if (timeout != sc->timeout)
197 		ichwd_tmr_set(sc, timeout);
198 
199 	/* reload */
200 	ichwd_tmr_reload(sc);
201 
202 	*error = 0;
203 	return;
204 }
205 
206 static int
207 ichwd_probe(device_t dev)
208 {
209 	(void)dev;
210 	return (0);
211 }
212 
213 static unsigned long pmbase;
214 
215 /*
216  * Look for an ICH LPC interface bridge.  If one is found, register an
217  * ichwd device.  There can be only one.
218  */
219 static void
220 ichwd_identify(driver_t *driver, device_t parent)
221 {
222 	struct ichwd_device *id;
223 	device_t ich = NULL;
224 	device_t dev;
225 
226 	printf("%s()\n", __func__);
227 
228 	/* look for an ICH LPC interface bridge */
229 	for (id = ichwd_devices; id->desc != NULL; ++id)
230 		if ((ich = pci_find_device(id->vendor, id->device)) != NULL)
231 			break;
232 	if (ich == NULL)
233 		return;
234 
235 	if (bootverbose)
236 		printf("%s(): found ICH chipset: %s\n", __func__, id->desc);
237 
238 	/* get for ACPI base address */
239 	pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
240 	if (pmbase == 0) {
241 		if (bootverbose)
242 			printf("%s(): ICH PMBASE register is empty\n",
243 			    __func__);
244 		return;
245 	}
246 
247 	/* try to clear the NO_REBOOT bit */
248 	pci_write_config(ich, ICH_GEN_STA, 0x00, 1);
249 	if (pci_read_config(ich, ICH_GEN_STA, 1) & ICH_GEN_STA_NO_REBOOT) {
250 		if (bootverbose)
251 			printf("%s(): ICH WDT present but disabled\n",
252 			    __func__);
253 		return;
254 	}
255 
256 	/* good, add child to bus */
257 	if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
258 		dev = BUS_ADD_CHILD(parent, 0, driver->name, -1);
259 	device_set_desc_copy(dev, id->desc);
260 	device_set_driver(dev, driver);
261 }
262 
263 static int
264 ichwd_attach(device_t dev)
265 {
266 	struct ichwd_softc *sc;
267 
268 	device_printf(dev, "attaching\n");
269 
270 	sc = device_get_softc(dev);
271 	sc->device = dev;
272 
273 	/* allocate I/O register space */
274 	sc->smi_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->smi_rid,
275 	    pmbase + SMI_BASE, pmbase + SMI_BASE + SMI_LEN - 1, SMI_LEN,
276 	    RF_ACTIVE|RF_SHAREABLE);
277 	if (sc->smi_res == NULL) {
278 		device_printf(dev, "unable to reserve SMI registers\n");
279 		goto fail;
280 	}
281 	sc->smi_bst = rman_get_bustag(sc->smi_res);
282 	sc->smi_bsh = rman_get_bushandle(sc->smi_res);
283 	sc->tco_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->tco_rid,
284 	    pmbase + TCO_BASE, pmbase + TCO_BASE + TCO_LEN - 1, TCO_LEN,
285 	    RF_ACTIVE|RF_SHAREABLE);
286 	if (sc->tco_res == NULL) {
287 		device_printf(dev, "unable to reserve TCO registers\n");
288 		goto fail;
289 	}
290 	sc->tco_bst = rman_get_bustag(sc->tco_res);
291 	sc->tco_bsh = rman_get_bushandle(sc->tco_res);
292 
293 	/* reset the watchdog status registers */
294 	ichwd_sts_reset(sc);
295 
296 	/* make sure the WDT starts out inactive */
297 	ichwd_tmr_disable(sc);
298 
299 	/* register the watchdog event handler */
300 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, ichwd_event, sc, 0);
301 
302 	/* enable watchdog timeout interrupts */
303 	ichwd_intr_enable(sc);
304 
305 	return (0);
306  fail:
307 	sc = device_get_softc(dev);
308 	if (sc->tco_res != NULL)
309 		bus_release_resource(dev, SYS_RES_IOPORT,
310 		    sc->tco_rid, sc->tco_res);
311 	if (sc->smi_res != NULL)
312 		bus_release_resource(dev, SYS_RES_IOPORT,
313 		    sc->smi_rid, sc->smi_res);
314 	return (ENXIO);
315 }
316 
317 static int
318 ichwd_detach(device_t dev)
319 {
320 	struct ichwd_softc *sc;
321 
322 	device_printf(dev, "detaching\n");
323 
324 	sc = device_get_softc(dev);
325 
326 	/* halt the watchdog timer */
327 	if (sc->active)
328 		ichwd_tmr_disable(sc);
329 
330 	/* disable watchdog timeout interrupts */
331 	ichwd_intr_disable(sc);
332 
333 	/* deregister event handler */
334 	if (sc->ev_tag != NULL)
335 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
336 	sc->ev_tag = NULL;
337 
338 	/* reset the watchdog status registers */
339 	ichwd_sts_reset(sc);
340 
341 	/* deallocate I/O register space */
342 	bus_release_resource(dev, SYS_RES_IOPORT, sc->tco_rid, sc->tco_res);
343 	bus_release_resource(dev, SYS_RES_IOPORT, sc->smi_rid, sc->smi_res);
344 
345 	return (0);
346 }
347 
348 static device_method_t ichwd_methods[] = {
349 	DEVMETHOD(device_identify, ichwd_identify),
350 	DEVMETHOD(device_probe,	ichwd_probe),
351 	DEVMETHOD(device_attach, ichwd_attach),
352 	DEVMETHOD(device_detach, ichwd_detach),
353 	{0,0}
354 };
355 
356 static driver_t ichwd_driver = {
357 	"ichwd",
358 	ichwd_methods,
359 	sizeof(struct ichwd_softc),
360 };
361 
362 static int
363 ichwd_modevent(module_t mode, int type, void *data)
364 {
365 	int error = 0;
366 
367 	switch (type) {
368 	case MOD_LOAD:
369 		printf("ichwd module loaded\n");
370 		break;
371 	case MOD_UNLOAD:
372 		printf("ichwd module unloaded\n");
373 		break;
374 	case MOD_SHUTDOWN:
375 		printf("ichwd module shutting down\n");
376 		break;
377 	}
378 	return (error);
379 }
380 
381 DRIVER_MODULE(ichwd, nexus, ichwd_driver, ichwd_devclass, ichwd_modevent, NULL);
382 /*
383  * this doesn't seem to work, though I can't figure out why.
384  * currently not a big issue since watchdog is standard.
385 MODULE_DEPEND(ichwd, watchdog, 1, 1, 1);
386  */
387